This invention relates to a novel continuous tubular structure forming method and apparatus and to a new continuous tubular structure produced thereby.
The present invention provides a novel method, apparatus and tubular structure which overcome the shortcomings of previous expedients. In addition, the method, apparatus and structure provide features and advantages not found in earlier technology.
The method and apparatus of the present invention may be employed by individuals with only limited mechanical skills and experience. Tubular structures can be produced by such individuals safely and efficiently without supervision utilizing the method and apparatus of the invention. The configuration and composition of the tubular structure can be changed easily. The method of the invention can be modified to form a variety of different tubular structures with the apparatus of the invention. Variations in physical dimensions, composition and surface appearance, etc. can be achieved. Even with such changes, uniform high quality can be maintained without difficulty employing the method and apparatus of the present invention.
A novel method of the present invention for forming a continuous tubular structure includes the steps of preselecting a liquid reactive resin forming material, a. particulate solid additive material, a porous tubular blanket and an inflatable bladder member disposed within the tubular blanket. The additive particles are mixed with the liquid resin forming material substantially continuously to form a substantially uniform mixture thereof. Substantially all of the additive particles are encapsulated with the liquid resin forming material.
The porous blanket/bladder combination is advanced through the resin/additive mixture. Part of the mixture is migrated through the blanket substantially uniformly to form a continuous resin matrix within the blanket.
The mixture-treated blanket is advanced along a preselected path. The bladder member within the treated blanket is inflated to form a bladder-lined tubular structure of a preselected cross section. The inflated tubular structure is placed into a preselected final configuration while the structure is flexible and has an adhesive outer surface.
Advantageously, a second resin/additive mixture is applied to the tubular structure in a preselected thickness. The second mixture preferably is formed by mixing the additive particles with the liquid resin forming material while tumbling the materials along a generally cylindrical path in a preselected orientation. The direction of the tumbling advantageously is reversed as the materials advance along the cylindrical path.
The orientation thereof may be changed along preselected sections of the cylindrical path. The orientation of the mixing sections preferably is monitored and adjusted to maintain it within preselected specifications.
Materials may be added sequentially along preselected sections of the cylindrical path. This is especially useful with multiple component resin forming systems. If desired, pressure may be applied to the tubular structure before its placement in a preselected final configuration.